Facebook and YouTube are competing to become the dominant social video platform.

YouTube CEO Susan Wojcicki joked that rival site Facebook "should get back to baby pictures" rather than attempt to become a video platform that competes with YouTube, according to a report on CNBC.

Wojcicki was speaking at Recode's Code Media conference on February 12 and was asked by journalist Kara Swisher whether she's concerned about Facebook's growing video ambitions.

"I mean you always have to take your competitors seriously, but you don't win by looking backwards and looking around," Wojcicki said.

Swisher pushed her to expand on that response, asking "what do you think they're doing?"

"I think they should focus on what they're focused on," Wojcicki said. "I think they should get back to baby pictures and sharing."

"I'm not an expert about Facebook. They're experts in it and they should do what's best for their business. And look, we should all compete for content. I build our business and I focus on what we need to do, and I know that we have a lot of things to do. You can always remind me of all the things that we need to do and we're going to keep doing them because that's the way that we're going to get stronger."

Facebook and YouTube both want to become the web's go-to video platform

Justin Sullivan/Getty ImagesWojcicki's shot at Facebook comes as the two companies are battling to control social video. Facebook has been ramping up the amount of video it shows in its news feed, and introduced new advertising options including pre-roll and mid-roll ads for creators.

For the first batch of Facebook Watch shows, Facebook reportedly spent $10,000 (£7,200) to $40,000 (£28,000) per episode for short-form series, and $250,000 (£180,000) to $1 million (£721,000) per episode for TV-length original series.

However, Wojcicki's comment does touch on an important point: Video is a relatively new part of the mix of content on Facebook, and the company has indicated that it's going to refocus its news feed on content from friends, rather than pages.

"When people are engaging with people they're close to, it's more meaningful, more fulfilling," said Facebook's director of research David Ginsberg in an interview with The New York Times, "It's good for your well-being."